Here is the full list of who signed:
Senator Tom Cotton, R-AR
Senator Orrin Hatch, R-UT
Senator Charles Grassley, R-IA
Senator Mitch McConnell, R-KY
Senator Richard Shelby, R-AL
Senator John McCain, R-AZ
Senator James Inhofe, R-OK
Senator Pat Roberts, R-KS
Senator Jeff Sessions, R-AL
Senator Michael Enzi, R-WY
Senator Michael Crapo, R-ID
Senator Lindsey Graham, R-SC
Senator John Cornyn, R-TX
Senator Richard Burr, R-NC
Senator John Thune, R-SD
Senator Johnny Isakson, R-GA
Senator David Vitter, R-LA
Senator John A. Barrasso, R-WY
Senator Roger Wicker, R-MS
Senator Jim Risch, R-ID
Senator Mark Kirk, R-IL
Senator Roy Blunt, R-MO
Senator Jerry Moran, R-KS
Senator Rob Portman, R-OH
Senator John Boozman, R-AR
Senator Pat Toomey, R-PA
Senator John Hoeven, R-ND
Senator Marco Rubio, R-FL
Senator Ron Johnson, R-WI
Senator Rand Paul, R-KY
Senator Mike Lee, R-UT
Senator Kelly Ayotte, R-NH
Senator Dean Heller, R-NV
Senator Tim Scott, R-SC
Senator Ted Cruz, R-TX
Senator Deb Fischer, R-NE
Senator Shelley Moore Capito, R-WV
Senator Bill Cassidy, R-LA
Senator Cory Gardner, R-CO
Senator James Lankford, R-OK
Senator Steve Daines, R-MT
Senator Mike Rounds, R-SD
Senator David Perdue, R-GA
Senator Thom Tillis, R-NC
Senator Joni Ernst, R-IA
Senator Ben Sasse, R-NE
Senator Dan Sullivan, R-AK